So if your motherboard doesn't support PWM, you could still use PWM fans if you have a ZM-MFC2?
Yep, I've got an old MB with no PWM connectors and I have a PWM fan in the power supply running off of this controller. Keep in mind though that only one of the 4 channels is PWM, the others are regular voltage-regulated. Like you said, you can
link several of those fans, but the downside is that all of them would be running at the same revs, which may not be desirable if you have them doing different things (intake vs PS or cpu cooling)
I was wondering what type of fan(s) you are using to get them running at 600 RPM, since I am unable to drop my Noctua-1200's below ~1020 RPM. If I set the Zalman to anything lower then this, it just cranks the fan speed up/down/up/.. and is not near silent at all.
If other users have experience with the Zalman and Noctua or Nexus fans, I'd be happy to hear, since I'm rather unhappy with it.
The 2 case fans that run at 600 are the stock Thermaltake fans that come with the Tsunami case. They are pretty typical 120mm fans, although pretty loud at 12V when using the molex connector. I believe the model # on those is TT-1125. I just did a quick little test and these things actually run steady at the 540rpm setting with actual revs between 510-530 (I didn't bother testing lower since it isn't practical- they're probably the quietest ones in my case @600, so you gain nothing by running them slower). The other fan I use is the Scythe Ninja's 120mm, which I run at 660rpm, but seems to stall around 600. Those are the voltage-controlled ones. The PWM-controlled fan in my power supply I briefly tested as low as ~300rpm (before I put it in the PS, of course).
With regards to your Noctuas, are you using the same controller? If so, might I suggest setting the rpm really high on the controller (ie: 1500), let the fans spin up and stabilize, then gradually keep decreasing the rpm set speed, waiting for the rpms to settle around the target point. I notice that sometimes if I have the fans running at higher speeds during gaming, and then drop the rpm setting (typically dropping speeds by half) close to the fans' stall point, they sometimes overshoot the mark, their voltage gets too low for the rpm sensor to pick up and the controller bumps up the voltage to compensate and you get stuck in a stall/over-rev loop. Very rare occurence, but annoying with that damm warning beep when the revs drop too low. Once you find the stall point by that method, just save the setting to one notch (ie: 60revs) higher, and it should be fine from the moment you boot up.[/i]